In a letter to Pruitt, the RFA said that while the waiver, which relaxes the RVP requirement such that E15 (15% ethanol) may be sold immediately in conventional gasoline areas in the covered states, the full potential of the waiver can only be realized if EPA relaxes certain additional regulatory requirements related to the sale of E15. The letter lists several other requirements that should be waived in order to make it possible to have E15 blends on the market to alleviate current supply shortages.